Toxic ash that billowed from an old municipal incinerator in Coconut Grove and left soil contaminated for more than 40 years after it was shut down does not pose a health risk to the surrounding neighborhood, county environmental officials said Monday.

But ash that may have been trucked and dumped at a nearby park creates a far greater risk and remains under investigation, said Wilbur Mayorga, chief of Miami-Dade’s Environmental Monitoring & Restoration Division.

The findings, announced at a neighborhood gym filled with about 200 residents, cap a prolonged investigation that has dragged on for more than two years and angered residents critical of the city of Miami’s slow response. Last month, the county finally began conducting its own tests after ordering the city to sample soil within a one-mile radius of the old incinerator site at 3425 Jefferson St. During that testing, officials discovered dangerous levels of lead, which can cause many harmful health issues, particularly among children, at Blanche Park at 3045 Shipping Ave.

During the two-hour meeting at Elizabeth Virrick Park in Coconut Grove, Mayorga, along with City Commissioner Marc Sarnoff, tried to draw a distinction between the two studies.

“The problem now is Blanche Park and that is undetermined,’’ Sarnoff said. “We don’t know where we are.”

Residents repeatedly expressed frustration at the confusing data, some particularly angry that the city reacted quickly after discovering contamination at Blanche Park, while taking two years to address questions about the incinerator that operated in the West Grove for more than 40 years. It was closed in 1970.

“One facility is an industrial facility and is completely fenced off with....a known history,” said Assistant City Manager Alice Bravo. “The other is a park being used by children with a letter from a regulatory agency saying to take immediate action.’’

The city has taken nearly 200 samples from about 20 locations in Blanche Park, with about five more locations left, said the city’s consultant, Eduardo Smith, of SCS ES Consultants. Because the park is covered by either artificial turf or asphalt the city installed last week, officials are only concerned with past exposure.

And they are particularly concerned about the high concentrations of lead, explained Samir Elmir, director of the Division of Environmental Health and Engineering for the Miami-Dade County Health Department. Lead can cause serious harm to one’s cardiovascular, nervous and reproductive systems, digestive tract, muscles and skeleton, blood formation and eyes and kidneys, according to the Centers for Disease Control and Prevention. Children are especially vulnerable to lead.

Based on findings expected to be complete in two weeks, Elmir said he can calculate the risk and decide whether to recommend parents have their kids tested.

In the meantime, Dawn McCarthy said her two daughters, and many other parents, are staying away from the park.

“We used to find chunks of glass in that sand all the time. Now we’re all looking at each other going, ‘Oh, that’s what that glass was,’ and we’re all very disturbed,” she said.

The city first discovered contamination at the old incinerator site in 2011 after proposing an expansion of the fire training facility now located on the land. The site is tucked into an historic black neighborhood, between a park and a community center for elementary and middle school students, and sits just over a mile southwest of Blanche Park.

The city notified the county. The county, which oversees environmental clean-ups, then ordered the city to determine the extent of the contamination as well as the risk it posed to residents within 60 days.

The city missed its first deadline, then a second.

Earlier this year, almost two years later, University of Miami graduate student Zach Lipshultz discovered the report detailing the contamination while investigating a nearby trolley garage that neighbors bitterly opposed. Tension, already high over the trolley garage being built for the neighboring city of Coral Gables, grew worse.

The Ministerial Alliance, a partnership among the neighborhood’s black churches, wrote letters to the county, the state Department of Environmental Protection and the U.S. Environmental Protection Agency asking for help.

At the meeting, Lipshultz, now a UM law student, along with three other fellows from UM’s Environmental Justice Project, questioned whether the county’s findings adequately addressed residents’ concerns and felt the simplified numbers failed to present a broader picture of possible contamination.

The law school is working with the university’s medical school to establish a disease registry, which would help residents like Andre Thompson, 59, who attended the meeting and said his uncle and aunt grew up in his grandmother’s house near the incinerator and both died from cancer.

In addition to the registry, UM law professor Anthony Alfieri, who created the Environmental Justice Project, believes an independent study should be conducted.

“We are highly skeptical of DERM’s findings and conclusions and strongly recommend additional independent testing and investigation by the EPA and other environmental/public health providers.”